Automatic trunking device and selective signaling apparatus.



No 848,120. v PATENTED MAR. 26, 1907.

A. A. MONSON. AUTOMATIC TRUNKING DEVICE AND SELECTIVE SIGNALING APPARATUS.

APPLICATION FILED NOV. 27, 1906.

4 SHEETS-SHEET 1.

1' VVENTOR Arron/15m PATENTED MAR. 26, 1907.

A. A. MONSON. AUTOMATIC TRUNKING DEVICE, AND SELECTIVE SIGNALING APPARATUS.

APPLICATION FILED H0127. 1906.

4 SHBETS-SHEBT 2.

AzgyzzaZAMozzabzz WIT/VELQSES I f/VVE/VTOA I A TTORNE Vs No. 848,120. PATENTED MAR. 26, 1907.

A. A. MONSON.

AUTOMATIC TRUNKING DEVICE AND SELECTIVE SIGNALING APPARATUS.

APPLICATION FILED NOV. 27. 1906.

4 SHEETS-SHEET 3.

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. I INVENTOR. ,W A Z ZL By I ATTORNEYS PATENTED MAR. 26, 1907.

A. A. MONSON. AUTOMATIQTRUNKING DEVICE AND SELEGTIV'E SIGNALING APPARATUS.

APPLIOATIOR mum 110121. 1906. v

4 SHEETS-SHEET 4.

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AUGUST ALVIN MONSON, OF ST. PAUL, MINNESOTA. AUTOMATIC TRUNKING DEVICE AND SELECTIVE SIGNALING APPARATUS.

No. sesneo.

Specification of Letters Patent.

l atented March 26, 1907.

Application filed November 27,1906. Serial No. 345,316..

To albwhom it may concern.-

Be it known that I, A eUsrArvmMoN.

State of Minnesota, have invented a new and useful Automatic Trunking Device and Selective Signaling Apparatus, of which the following is a specincation- This invention relates to telephone systems, and has for its principal. object to provide. a system by which outlying subscribers may be connected to a central station at very .small expense- When suburban subscribers. are to be connected to the central station of a city or town, it is often a matter of considerable expause to run a wire or wires for either com-- mon return, grounded, or full-metal circuits, the expense of erection being in many cases prohibitive. One of the ordinary methods of overcoming this difficulty is to provide a party line system where a number of subscribers are connected on the same line, each having a distinctive call; but this is a matter of considerable annoyance where the calls are sounded at every phohe and where the connections are such that any subscriber may overhear the conversation of another. For party-line systems selective devices have con employed; but these as a rule are expensive and'require the services of an expert to maintain them in working order. Incar- 'rying out the present invention provision is made for connecting two, three, or a dozen or more outlying subscribers stations to a central point, which may be a distributingpole, and then connecting this central point to the main central station-by a trunk-line.

A further object of the invention is to provide a selective mechanism. that is common to a group of subscribers as distinguished from the ordinary selective mechanism,

be disconnected from the line when any one subscriber connects his station to central.

A still furtherobject of the invention-is to provide means whereby a subscriber. may

connect his station to central and at the same time out out all other subscribers of the group by simply operating a push-button, switch,

or the hke or by simply removing the receiver from the hook, it being unnecessary to employ any specially-constructed or com licated mechanism at the subscribers station for this urpose.

A still further object of-the invention is to provide a system of this kind in. which after a call'from any one of a group of subscribers the central operator may connect any one of the group without sounding the call-bells of theothers and still maintain all .of the remaining lines disconnected.

A still further object of the invention is to provide mechanism which may be used in connection with systems where the energy is supplied at the subscribersstations or where Y central-station energy is employed.

With these and other objects in view, as will more fully hereinafter appear, the invention'consists in certain novel features of construction and arrangement of parts, hereinafter fully described, illustrated in the accompanying drawings, and particularly pointed out in the appended claims, it being understood that various changes in the form, proportions, size, and minor details of the structure may be made without departing from the spirit or sacrificing any of the advantages oi the invention. a

In the accompanying drawmgs, Figure 1 is a general diagram, illustrating a telephone system arranged in accordance with the Fig. 2 is a detail view of one of 9 5 the circuit-closing electromagnets of the ceninvention,

tral station, showing the condition of the parts when the electromagnet is energized. Fig. 3 1s a detail view of the selecting device.

Fig. 4 is a detail view illustrating amodiiication of the means for closing the circuit at the subscribers station when central-station energy is used. Fig. 5 is a diagram of the wiring where central-station energy is used. Fig. 6 is a diagram of a grounded system.

Similar numerals of reference are em-. ployed to indicate corresponding parts throughout the several figures of the drawings.

The main central station A is connected to what may be termed the branch central station Bby a trunk-lino, comprising two wires and 11. Thisbranch central station may be arranged at any convenient point, the apparatus being housed in a suitable casing and placed,for instance, on a distributing-pole located at some convenient point, from which'conn'ections maybe run to the subscribers stations, two of which, C and I), are illustrated in Fig. 1, although there may be any number of subscribers connected to this branch central. The apparatus shown in the diagram is limited to a group of six subscribers; but these may of course be increasedby altering the capacity of the selective device. Each subscribers station is connected to the branch central by. two wires 12 and 13.

At the branch central there is an electro magnet 15 for each subscriber and a single electromagnet 16 common to all of the subscribers, this second magnet 16 serving when energized by any one subscriber to cut outall remaining subscribers and prevent them from overhearing a conversation.

The electromagnet 15 is provided with a ivotally-mounted armature 1.7, from the rec end of whichrises a rod or arm 18, that is arranged to engage and elevate a small block or stri 19, formed of insulating material, when t e electromagnet, 'is energized.

Arranged above the magnet is a series of contacteprings 20, 21, 22, 23, 24, 25, 26, 27, and 28, all of which are carried by a block at one end and are insulated from each other at this point. The outer block or strip 19 is firmly connected to the strips 2], 24, and 27 and serves to simultaneously move said contact-strips when the electromagnet is energized.

On the frame of the electromagnet 16 IS a block 30 formed of insulating material and carrying two contact-strips 3i and 32, that normally engage each other, the upper strip 32 being movable by a rod or arm 33, that is carried by the armature 34 of the magnet, and when the latter is energized the armature is raised and the strip 32 is forced from engagement with the strip 31, breaking circuit between them.

At tlic branch central station is a battery 35, one )ole of which is shown as grounded at 36, W ilc from the opposite pole extends a wire 37 to' contact 31, and when contact 32 is down in engagement with contact 31 the circuit may be traced to wire 33, contact 20, contact 21, wire 39. electromagnet 15, wire 13, to the subscribers station.

At each subscribers station is arranged a means for closing this circuit.

in the construction shown in Fig. 1 two spring-contacts 42 and 43 are employed, said contacts being insulated from each other and the contact 43 being under the control of a push-button 44, which may be pressed inward by the subscriber in order to connect it to the contact 42. When so pushed in, the contact 43 is held by a pivotallymmuutcd catch 45, so as to hold the circuit closedxpermanently, said circuit being completed from the contact 43, through wire 46, to ground. At the subscribers station is shown. a re ceiver-hook switch 49, which has an arm 50, arranged to engage a small cam. 51 on the lower side of the catch when the receiver is returned to the hook, and when this is done at the completion of a conversation the catch 45 is elevated and the contact 4-3 is released, so as to break the circuit. This same operation, however, may be accon'iplishcd automatically without the employment of a push-button and catch. 45, it being siin jily necessary to employ a Cildll lil'lt. lug 52-; on the spring 42 to be engaged by the arm. of the receiver-hook when the hook elevates after the removal of the receiver, this 1 peratiou automatically completing the circuit When the receiver is replaced on the hook, the arm '50 will leave the cam 53 and the ciruit will be automatically broken.

The subscribers stations are also providol with the usual local circuits, including the receiver and transmitter and a call bcll 57. A small magneto-generator 58 is also shown at each station in Fig. 1, although in some in stances this may be omitted where ,'.cntralstation energy is employed.

When a subscriber wishes to call another, he presses button 44 or otherwise engages the two contacts 42 and 43, whereupon a circuit is closed from the battery 35, through wirc 37, contact 31, contact 32, wire 38, contact 20, contact 21, electrontiagnct 15, wire 13, contact 42, contact 43, wire 46, to ground, and thence back to battery. This energizes the electromagnet l5, and the armature 17 is drawn upward, moving the contact :21 into engagement with the contact 322. The rcsiliency of the contact-spring 20 is such that as the spring 21 moves upward the spring 20 will followit and will not break contact therewith until .21 has made contact with 22, when it breaks away, and 23 and 26 break away from 24 and 27 as soon as the latter have risen and made contact with 25 and 23, rcspectively. Thus the circuits will be trans-- ferred without any break.

It will be noted that a branch 60 of the wire 37 runs to the winding of the clcctromagnet 16, and from the elcctroinuuuct extends a wire 61 to the contact 22, so that us soon as the circuit is transferred to contact the course of the current will be from buttery, through wire 37,\virc co, clcctroinn ni-t 16, wire (51, Contact 22, Contact ill, \i'irc flu, windin 15, wire 3, to the subscrihcns station and ground. 'As soon as the clcctromagnet 1G is energized its arumturc 34 is at tractcd, and being elevated the contact 3:2 will be moved out of engagement with the LCD ;be,broken for all subscribers.

noted that this single electromagnet 16 is station no other subscriber in that particular seaieof contact 31, and the circuit at this point will It is to be common to all oft-he subscribers, and when "once a circuit is broken between 31 and 32 by the-closing of the circuit at any subscribers group can'make a call'to central nor can he listen to any conversation" being carried on ever the line. It is important in this connection to note that when: the contact 20 moves. up following the contact. 21 there is merely a transfer of the circuit. Without breakage; otherwise the electromagnet 15 will be delenergized.

' Whenthe electromagnet 15 was energized and block 19 was moved up, the contact .24 moved from contact'23 into engagement with contact 25'and' the contact 27 .moved from engagement with contact 26 into engagement with the contact 28; The result of this is that acircuit is closed through the trunk-lines 1 0 and 11, which circuit may be traced from the subscribers station throughwire 12, contact 27, contact 28, wire- 11 to the switchboard-jack 62, to calling drop-magnet 63, back over wire 10 to contact 25, contact 24, wire 64, and Wire 13 to the subscribers station. The central-station operator will then plug in in the usual manner and ascertain the number of the station with Which the subscriber desires to be connected, and if the station to be called is at 'any point outside the group in which the calling subscriber is located the connection is made in the or- Should the station to be calling subscriber, it becomes necessary to make the connection in another manner.

At the branch central station is a selector, including a plate or disk 70, carrying an an nular series of contacts 71, there being as,

many pairs of contacts as there are subscribers in the group, six pairs being shown in the present instance, and those of each pair being disposed diametrically o posite each other. At the center of the p ate or disk is a short shaft 72, on which is mounted a disk 7 3, formed of insulating material, and a ratchet-wheel 74, the latter being provided. with teeth of a nunibercorresponding to the number of contacts, and these teeth being engaged by a pawl 75, that is carried by a lever 76. This lever has an'arrnature 77, that is arranged within the field of force of an electromagnet 78, and each time the electromagnet is energized the pawl will be operated to advance the ratchet-wheel to the extent of a single tooth. On the periphery of the drum 73 are two spaced contact-rings 96 and 97, which are connected, as shown in Fig. 3, to metallic contact tongues or brushes 98 and 99, these tongues or brushes being arranged to engage the contact-buttons 71. The contact-rings 95 and 97 are engaged by brushes and 81, and these are connected to the trunk-line wires 10 and 1.1 by branch Wires 82 83, respectively. Leading from each pair of buttons are Wires 84 85, Which are connected tothe contact-springs 2S and 26, re- 'spectively, there-being one electromagnet l5 and one set' of contact-springs and one pair of contact-buttons for each subscriber, as previously described.

At the central station is a reiwiluble disk 86, having peripheral tongues 87, arranged to engage and depress a contact spring 88, the latter being movable into engagement with a contact-spring 89. 'lhe contact-spring 89 is connected to one pole of a battery 90, the opposite pole beinggrounded, while the contact-spring 88 is connected, by a Wire 91 to the trunk-line '10. 'In some cases wire 91 is extended independently to electromagnet .78, and Wire 82 joining it to trunk is omitted.

From the trunk-line at the branch central station leads a wire 82 to the selec tor-electromagnet 78, and-from thence to ground.

If the central operator wishes to call a subscriber in the group, either at the request of another subscriber in that group or someone side station, she turns the disk 86 for a distance' corresponding to the number of the subscriber to be called, thus, making and breaking contact between the springs 88 and 89, and each time the selectordisk is turned to the extent of a single tooth and the contactsprings 98 and 99 firmly rest on the con-- tact-buttons 71, belonging to thesubscriber to be called. Assuming that the springs 98 and 99 make contact with the terminals of the conductors 84 and 85, the calling or sig-.

nal circuit may be traced from the central station over wire 10, wire 82, contact 80,

ring 96, brush 99, one of the buttons 71, wire 84, contact 23, contact 24, wire 64, wire 13 to subscribers station, back through wire 12, contact 27, contact 26, wire 85, the opposite button 71, brush 98, ring 97, contact-brush 81., wire 83 to trunk-wire 11, and back to the central station, it being remembered that the. electromagnet 15 of the 'SUbSCIllHJl to be called has not been energized, and the contacts 27 and 26 and 2 and 23 are therefore in engagement with each other. The oper-' ator connects the called and calling stations, and rings of the trunk, thus notifiwing both parties that the connection has been made. When finished, the subscribere'rhig oil in. the usual way, it being merely necessary to replace the receiver on the hook to effect the breaking of the contacts 42 and 43. This denergizes the electroinagnets 1 5 and: 16., and the operator then turns the seloct0ki--3lisl( 86 the rest of the Way around, leaving the line in conditionfor another call.

the employment of the central-calling device the central station can at any time select and privately call any of the subscribers in another group, and after being established from the battery through coil 16 tion, diverting the current to central after called the subscriber should press his button inorderto out out the selecting device and operate ,the electromagnets .15 and 16 for the purpose oi cuttingout the balance of the "group, thus insuring the utmost rivacy. Meantime the central operator may restore the disk 86 to ze'roin order, to save time in.

case there should be a'subsequentycall for another subscriber in the cup;

In Fig. is illustratedt e arrangement of thewiri e where'lcentral-station energy is used, andm this case the push-button 44 and catch 45- are omitted, as previously described,- thecircuit being closed automatically where the receiver is removed from the hook. When the circuit is closed at the contacts 42 43, the current will flow through the magnets 1'6, as bef'ore, thus energizing them, and thereby causi the'closure of the contacts 21 22, 24 2.5.,en 27 28. Another circuit will then be to coil 15,;througli contacts 21 22, thence through the bells 57 to contacts 27 28, thence to conductorll, thence through jack oz to 'call-drop-magnet 63, to groun the battery, impedance 121 between the conand back to 'tacts 42 43-, and to ground at theilocal Sta-- theinitial energization of the magnets 15 16. T arra ement would also furnish current to the cal ed station for talking purpose after it has been selected by the operation of the selecting mechanism.

For a grounded circuit one side of the drop would .be severed and grounded, as shown in Fig. 6, and in this case the top of the spring.

of the jack would be omitted, The upper condenser 100 is omitted and the connection between the wire 82'and the selector-spring 99'is also omitted, while only a single selecting-spring is used. In this case it is not nection, an electromagnet at the branch central station for each of the subscribers and under the sole control of the subscriber, contacts under the control of said electromagnets for closing connection between the trunk-line and the subscribers station when the electromagnet is energized, and an additional electromagnet connected in multiple with the entire group of subscribers stations,

and contacts under the control of the addi-' tional magnet and through which all connections must be primarily made, the energizing of the additional electromagnet by any sub scriber cutting out all of the remaining sub scribers of the group.

In telephony, a main central station, a branch central station connected thereto by a trunk-line, a series of circuit-closing cleo tromagnets arranged at the branch central station, agrou -0 subscribers. stations, each of which is in ividually connected to one oi Said-electromagnets, a circuit-breaking elecmagnet arranged at the branch central station and connected in multiple to an entire group of subscribers stations, and contacts under the control of the electromagncts for closing connection between the trunk-line and any subscriber, and automatically breakdug the circuits of the remaining subscribers of the group.

3. In trunk-line telephone systems, a group of subscribers stations connected .to a

ranch central station which forms one terminal of the trunk-line, electroma neticallyactuated contacts arranged at t e branch central station andconnected one to each of the subscribers stations for closing a clrcult between the trunk-line and the calling subscriber, and an electromagnetically-controlled circuit-breaking mechanism connected in multiple to the group of subscribers and operable by any subscriber making a call for cutting off communication between all of the other subscribers and the trunk-line.

4. In trunk-line telephone systems, a branch central station formin one terminal of the trunk-line, a series of Electromagnets arranged at the branch central station, contacts arranged adjacent to each magnet and under the control of its armature, the terminals of the trunk-line being connected to two of the contacts of each set, a roup of subscribers stations connected eacli to one of the electromagnets and also to contacts under the control of the electromagnct to which it is connected, whereby energizing of the subscribers line and electromagnet connects thesubscribers station to the trunkline, and a circuit-breaking eleot-romagnet having contacts under the control of said armature, the contacts being connected in multiple with the entire group of subscribers stations, whereby on the energizing of the circuit-breaking electromagnet by any subscriber, the connections of the remaining subscribers of the groupwill be broken.

5. In telephony, a main central station, a branch central station, a trunk-line connecting them, an electromagnetically-operated selector-disk arra qed at the branch central stationan'd vcontro able from the main ceniral station, a group of subscribers stations connected to the branch central station and under the control of a selecting device, a circuit-closing electromagnet arranged at the branch central station for each subscribers station, contacts under the control of said electroniagnet for closing circuit between the In testimony that I claim the foregoing as subscribers station and the trunk-line, and a my own I have hereto alfuted my signature in circuit-breaking electromagnet arranged at the presence of two witnesses.

the branch central station and common to AUGUST ALVIN MONSON. all of the subscribers stations for cutting out Witnesses:

all of the group of subscribers except the one J. M. ANDERSON,

making a call. IDA L. FALK. 

